Yeah there's a lot of problems in SF4, but there are some good things too.
I don't know how effective Gouken is, but his design is interesting. No dragon punch, but a super and ultra dragon punch. A high counter and low counter that act somewhat like a dragon punch, but worse because he has to guess high or low and it loses to the "breaking glass" moves, like Cammy's cannon spike. The ex counter doesn't require you to guess high or low though. I beat Cammy's ultra once with an ex counter, but got hit the second time I tried. Not sure what's up with that. Also, using the counter drains your life and slowly refills it, like using a focus attack. This is an advantage for the most part, because it means your ultra guage is even more full than usual. Because his ultra is guaranteed off a normal throw (and easy), it's basically a throw super...that doubles as the occasional dragon punch super if you really need it. Ironic that landing it is so easy that it's a better "throw super" than Zangief's, at least for me.
It's painful dealing with Zangief's bad-feeling jump, as if he is a flea of some sort, and not having his hop move. And not having his low fierce from Alpha 2 and 3. But his SPD is good, with jab having ridiculously long range (great!) but low damage. SPD startup time is 2 frames, which is bad for any other Street Fighter but buff in SF4 because other throws are so slow. Opponent trying link combos on you? Mash out a jab SPD and force them to have perfect timing. Lariat is also amazing, as it always is in just about every version of Street Fighter. I could be completely wrong about this, but Zangief seems strong against Rufus and Crimson Viper (see below), but against most characters, I feel like I only win when they make mistakes. I hear he is considered very strong, but I'm not sure how you'd beat a good Ryu or Sagat. There must be a million videos on that though.
My friend plays Crimson Viper, who seems like Crimson Eddie from Guilty Gear. Eddie can invite hell (the ground spike thing), frc (cancel), instant air dash slash. The effect is you get hit from below, then a split second later, hit from above. C.Viper can do the same thing with that ground punch thing that makes dust fly up from across the screen, cancelled into a super jump then into her air flame kick thing. If you do it right, this stuff hits very fast, indeed. She can also do a bunch of bullshit crossups with that air flame kick that beat out even dragon punches if she does it right (goes behind the dragon punch and hits it usually). Not to mention her slidey punch, short, slidey punch frame trap. If you do almost anything, you get hit by short into slidey punch. I think that's how it goes, I don't know exactly. I found that picking Zangief and doing lariat negates her entire bullshit crossup game, which is fine with me.
After the initial shock of how amazingly terrible Vega is, I kind of like him in a Dan sort of way. Winning with him seems like some kind of joke to humiliate the opponent. His roll is absurdly slow ("hey guys, I'm going to duck down and start rolling, what do you think of that?"). His wall dive is also an april fools joke, moving so slow and being so vulnerable as to as to inspire actual laughter from my opponents. A terrible flip kick and seemingly bad ultra round out his moves. That said, at least he has a decent slide, good pokes, and his good jump fierce and jump strong. On the one hand, it's sad to see him in this pathetic state, but on the other, I have to admit I had fun trying to scrape out wins with him against an onslaught of focus cancel combos and links and so forth. I don't even know a combo with Vega.
Bison's safe scissor kick seems dirty somehow. I'm always up for abusing a safe attack though so doing it all day is great. You do have to low jab, low jab, low jab, low short, scissor kick to play him though (or stick a low forward in there). I can do it somewhat ok. His slide is good, his scissor kick is good, his headstomp is pretty good. Too bad his psycho crusher is worse than even the greatly toned down version in Super Turbo. Also too bad that I can't seem to do his ultra without accidentally teleporting half the time. What's up with that? His ex scissor kick going through fireballs seems like overkill. It's not like fireballs are as powerful as in SF2 series, and he didn't need it there. His stand medium kick is a decent poke and his stand roundhouse is a great poke even though it's angled up (boo). Luckily, it has a totally wonky hitbox that allows hit to hit as if the graphics for it were straight out, instead of angled up.
I don't know what's up with Rose's links. Either I can't do them or her combos from Alpha 2 don't work anymore, I don't know. She seems ok. Her low strong is no longer the terror it used to be in Alpha 2, but her new semi-broken abuse is her Ultra. It slices, it dices, it makes toast. It hits jumping opponents, attacking opponents, throwing opponents, ultraing opponents. It's everything you could ever ask for in a move. Too bad I get qcf x 2 + PP instead of PPP half the time, which wastes my super meter and gets me killed because the super doesn't have a practically half screen hitbox like the Ultra. Remember kids, you always have an ultra in Street Fighter 4, so you might as well have one that hits anything on the screen, cleanly.
Some characters I'm pretty unhappy with, but at least some are fun. I really wish I could play a version without wonky jumps, way too floaty air recoveries, way too long knock downs, and the general "stuck in jello" feel that runs through the game. That would let the good parts shine more...